The City of San Diego knows a lot about the drinking water it delivers to your doorstep. It conducts hundreds of weekly tests throughout the city measuring its water for contaminants, chemicals and whether or not it is corrosive at different distances from city treatment plants.
But once that water leaves public water mains and enters your service lines to come through your faucet, public utility experts know very little about what’s in it.
Federal regulations only require the city to test 54 homes every three years for lead and copper. Because every household’s piping is different, it is very difficult to know where exposure to lead or other contaminants remains high inside a home.
“It is often said that ‘there are no lead pipes in California.’ What that really means is that there are no lead pipes that people know about,” said Professor Marc Edwards, a civil engineer and water expert with Virginia Tech.
Because the city documents no lead pipes in its distribution system, it is required to test a very minimal number of homes, and it must prioritize testing of homes built between 1982 and 1986, according to rules set by the federal Environmental Protection Agency. The logic is these homes are the “newest” ones that are likely to have lead solder before it was banned in 1986. Because solder is worst when it is “new,” theoretically, these homes would have the highest risk for having lead in water in homes.
“Now, when the law was written in 1990, that may have been true. Those houses were 5-years-old or so,” said Edwards. “Whether it is actually true or not now, no one really knows.”
In San Diego, the city tested homes for lead in water primarily in Del Mar, Scripps Ranch, Bay Park and Linda Vista in 2014. Areas where lead has been discovered in school water or where kids have shown elevated blood lead levels at higher rates, like Grant Hill, San Ysidro and Mountain View are barely tested or not tested at all.
NBC 7 Investigates made this map showing where the city conducted its 2014 lead and copper testing in homes.
The city declined to release exact addresses, but provided primary streets with the nearest cross streets for where it did the tests.
During its last round of lead testing, only three homes had any detectable levels of lead in the water. A home in Old Town had the highest amount with 146 parts per billion, which is nearly 10 times the limit that alarms federal regulators. But, because more than 90 percent of the homes tested fell below that threshold, the City of San Diego’s water is in compliance with federal regulations for lead.
Lead is a dangerous neuro-toxin and its negative health impacts can be particularly damaging in young children. Health experts say there is no safe limit of lead in water.
The city does a lot of its required testing for lead in homes in Linda Vista. In fact, nine of the 54 tests it conducts every three years are in one condo complex.
Linda Vista resident Ed Thomas said people have had concerns with their water there and wishes the city did more than the required minimal testing.
“I think if they’ve already seen problems, they should increase testing,” Thomas said. “Cause everyone should be safe, right?”
A spokesman for the city’s public water utility said the city tests neighborhoods that have the highest risks for lead coming from taps, which are homes built between 1982 and 1986.
One of the reasons the city only has to test 54 homes is because it has no known lead service lines.
NBC 7 asked Linda Vista resident Thomas if that puts his mind at ease.
“I guess so, but you know what? If you test it, then you know for sure," he said.
San Diego reports no lead pipes, but it has a lot of pipes and water mains made of material listed as “unknown,” according to data and information with the city and SANDAG.
In 1984, the EPA conducted a survey of 153 public water systems across the country to determine the extent of the use of lead pipes. San Diego responded it could not offer any estimate of the number of lead service lines remaining in the city.
A 2008 article in the National Institute of Health estimated that because San Diego continued permitting the installation of lead service lines, it likely had a significant number remaining.